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Industrial
Scrap:
Any plastic resin or products, such as factory regrind
and plant scrap, recycled outside of the primary manufacturing
facility. Also referred to as post-industrial or pre-consumer
plastics. (1995 post-consumer plastic Plastics Recycling/Recovery
Rate Survey, Glossary of Terms, R.W. Beck & Associates).
Injection Molding:
A process that involves transmitting melted resin into
a mold's cavity; the molten resin then cools and solidifies,
and the finished piece is ejected from the mold. (Modern
Plastics Encyclopedia 1995).
Impact
Strength
Impact Strength characterizes material behaviour under
high speed loading. Pendulum and falling weight type
testers are applied here. Specimen can be either plaques,
notched or unnotched bars or parts of finished products.
There are several impact methods like Charpy impact
test, instrumented puncture test and tensile impact
test. Generally impact test shows the energy which is
needed to break or puncture specimen under specified
conditions. In some tests it is possible to accurately
record force - deformation transient curves and calculate
specific parameters describing material behaviour under
impact loading.
Injection
molding
A repetitive process in which plastic is melted and
injected into a mold cavity where the article is cooled
down. After cooling, the mould opens and the article
is ejected. ). The melt is prepared in a screw setup
similar to an extruder; the screw acts in melting and
homogenizing the polymer while slowly retracted to build
up the melt reservoir necessary for the injection step.
Then, the screw is used as a plunger in a forward movement
to inject the melt through the runner , a manifold in
case of a multiple mould and the gate into the mold.
In the injection molding process, filling of the mold
and solidification takes place partially at the ssame
time, resulting in a very complex morphology in case
of semicrystalline polymers.
Ionic
polymerization
A chain polymerization in which the kinetic-chain carriers
are ions. Usually, the growing chain ends are ions
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Plastic
Brief